The only lawns that need watering on a regular schedule are those that are overseeded with ryegrass.
If you don't have ryegrass, you should turn off your automatic sprinkler system. You can always turn it on if we go extended periods with no rain.
When the grass does go dormant, how much should you water? The majority of the root system of warm-season grasses dies when the grass goes dormant, so all the stored food reserves for next year's growth is in the stolons (runners).
You really shouldn't have to water grass when it is dormant but that doesn't mean you want it to get bone dry. If the grass gets dry because we have a lot of cold, dry winds, you could possibly have some desiccation of the grass. Say, if we were to go about two or three weeks and don't get any rain whatsoever, you would want to give the grass just a light watering of around 15 to 20 minutes, which would be enough to wet the stolons. So the goal is not a good soaking as you want to do when the grass is still actively growing. But we rarely if ever go this length of time during the winter with no rain at all.
It is important to keep a healthy lawn over the winter because, depending on the variety of your grass, you will decrease the likelihood that it has some dead spots (winterkill) next spring when it comes time to green up. And in most cases, a healthy lawn will green up faster in the spring.
When you continue to water three days a week like it is still summer, not only are you wasting water, but it can be detrimental to other plants in the landscape. You are wasting lots of money, too. You are paying for water your grass and plants don't need, and you are causing your sewer bill to be higher for an entire year, because your sewer bill is based on the water usage for the months of December, January and February.
Not only are many people continuing to water too often, but they are continuing to have their sprinklers come on during the early morning hours. Early morning watering is dangerous during the cold months because most sprinklers are wetting the sidewalks and streets and this creates a hazard to pedestrians and vehicles when the temperatures drop below freezing. If the time comes that you need to turn on your sprinkler, make sure the temperature is above freezing.
Of course, newly planted shrubs and winter annuals can need regular watering during the fall and winter. These are normally isolated areas that can be hand watered. But don't overwater flowers such as pansies because they definitely don't like wet feet. Hand water them well, then don't water them again until they need it.
Invest in an inexpensive moisture meter. You can stick this in the ground a few inches next to annuals or shrubs to see if the ground is still moist or if it is dry. This will go a long way in preventing overwatering.
The meters are also great for letting you know when to water plants in containers.
I have often said that the worst thing to ever happen to a landscape is the in-ground automatic sprinkler system. This is because of the set-it-and-forget-it mentality. Years ago, we watered plants only when they needed it because we had to go to the trouble of dragging a hose out and hooking up a sprinkler to it.
With the proliferation of automatic systems, we see many more plant diseases and plant deaths caused by overwatering. A sprinkler system's controller should be changed as the seasons change. There is a big difference in the water needs of plants when it's 95 degrees, there is 14 hours of daylight and plants are growing, versus when it's 60 degrees, there is 10 hours of daylight and they are not growing. By adjusting your watering for the seasons, your lawn and the rest of the plants in your landscape will be healthier.
REACH SID MULLIS, THE DIRECTOR OF THE UNIVERSITY OF GEORGIA EXTENSION SERVICE OFFICE FOR RICHMOND COUNTY, AT (706) 821-2349 OR SMULLIS@UGA.EDU.